Its a grounding kit, older Jap cars car suffer from bad grounding which can impact on idle speeds and the electrical system. When you turn your aircon on, you might find your dash lights dim - fitting a grounding kit will resolve this sort of minor issue.
Muad_dib77 wrote:Also if there's a slight buzzing in your stereo - and you KNOW the stereo ground connector is wired correctly - and ground kit may help..
A ground loop isolator will also help out in this instance